I am using this mouse for last 5 months. The problem with this mouse is 1. It is weighing too much. It was brillient if they have used a single AA or AAA size battery that last for atleast 12 months. What is the fun in giving longer battery life using a number of batteries ? 2. The buttons are bit harder to press. If u have to use this mouse for longer period of time u will definately feel this. Otherwise it is a fentastic mouse I am running this mouse with a single battery. It is working !!!